However vigorously Washington defends the fact that the United States stands accused of spying on a loyal ally, Germany, the allegations are an embarrassment for Washington and risk fraying America’s usually sturdy relations with Berlin. But the damage may not be very serious.

However, is it really necessary that our nation’s secret service conduct espionage against America’s best friends? After all, by agreement the United States, Canada, the United Kingdom, Australia and New Zealand do not spy on each other.

Shouldn’t Germany and other post-Cold War allies enjoy similar immunity?

The first chapter in this awkward international scandal occurred last fall when it was discovered that American intelligence operatives were monitoring calls on German Chancellor Angela Merkel’s cellphone.

An oddity: Of all the international leaders President Barack Obama deals with, Merkel has probably been his closest ally. And it appears he may not have known about the phone hacking.

Obama’s response was that the fact that America’s intelligence operatives have the capacity to engage in such espionage doesn’t necessarily justify it.

The dust seemed to settle for a while, although the personal relations between Obama and Merkel had clearly been badly shaken.

Then, last week, the Germans accused two of their own intelligence agents of spying for the United States. And this time the situation was more complex because one of the German agents was also accused of spying for Russia.

In fact, it was during the investigation of the second agent’s ties to Moscow that the Germans learned that he also was on Washington’s payroll. They didn’t exactly “discover” his ties to the American espionage agencies because the agent volunteered the information that he’d passed 218 German intelligence documents to the United States.

These disclosures clearly irked Merkel, who apparently believed, perhaps somewhat naively, that in peacetime these sort of things couldn’t happen. Or maybe it wasn’t naivety at all. Perhaps, for her own domestic political reasons, she felt the need to express her outrage.

“We no longer live in the Cold War era where everyone is suspicious of everyone,” Merkel said during a television interview Saturday. Instead, she continued, the secret services should “concentrate on important issues.”

Given the current tensions between Russia and Ukraine – tensions centered on the volatile issue of whether Ukraine, formerly part of the Soviet Union, will become a trading partner with the European Union or strengthen its economic ties to Moscow — it would seem that Merkel might consider that an “important issue.”

But she went further than giving interviews. One day after discovering the spy in Germany’s own service, Merkel demanded that the United States recall its top intelligence official in Berlin. That dramatic action raised the tensions between the two allies to new levels.

On Friday, Germany’s foreign minister, Frank-Walter Steinmeier, said that under the circumstances, the expulsion of the top American intelligence agent in Berlin was “inevitable” but that nevertheless the two nations need to get along if international issues are to be addressed effectively.

“We need and expect a partnership (with the United States) based on trust,” he added.

And allies are maintaining a diplomatic partnership. Secretary of State John Kerry met with Steinmeier yesterday to discuss an unrelated issue, the joint German-American effort to negotiate a satisfactory solution to the long-standing problem represented by Iran’s nuclear program.

And Merkel herself said Saturday that “we work very closely with the Americans, and I hope that will continue.”

She surely wants Obama to promise there will be no further espionage embarrassments.